The present invention relates in general to fluid delivery systems, and more particularly, to spray nozzles and spray system assemblies which are susceptible to quick coupling to, and uncoupling from, a variety of fluid delivery systems.
Spray nozzle assemblies are used, for example, in several industrial, agricultural and commercial applications in which it is necessary to remove the spray tips for various reasons, such as inspection, cleaning, replacement of worn spray tips, or substitution of spray tips to change the spray pattern or discharge rate. It is therefore important that such spray nozzle assemblies be quickly and easily assembled to, and disassembled from the fluid delivery systems.
Many nozzles have been proposed and marketed; however, the assembly and disconnection of these nozzles is generally not readily possible without skill and tools, which may be costly and inconvenient. Such nozzles are exemplified by U.S. Pat. No. 3,705,693 to Frantz, entitled "Means for Sealing Fittings and Nozzle Assemblies at Extremely High Pressures" and U.S. Pat. No. 2,618,511 to Wahlin, entitled "Stirrup Nozzle", both of which are incorporated by reference.
The Frantz patent describes means for sealing joints subjected to extremely high fluid pressures in the order of 70 thousand pounds per square inch. An elastic member is subjected to moderate mechanical pressure by the components of the joint to be sealed, and then it is subjected to extremely high fluid pressure, whereby the elastic member is deformed between the components of the joint so as to seal the joint against leakage. However, this sealing means is not used for nozzle attachment, alignment or quick uncoupling.
The Wahlin patent relates to a stirrup nozzle for attachment to fluid supply pipes. The nozzle includes a nozzle body and a loop or stirrup extension which encircles the tube. At the stirrup end the nozzle body is internally threaded to accommodate a threaded plug, and the pipe is provided with an opening through the side wall thereof to receive an outer end portion of the plug. However, this nozzle design requires tools for uncoupling and alignment.
Although various conventional quick disconnect nozzle couplings have been prepared for pipe connections, the orientation of these nozzles within the couplings cannot be easily adjusted. In this respect, agricultural sprayer systems often operate in adverse environments with poorly defined and highly variable target geometries. The operating parameters of the agricultural field sprayers are typically set by the operator at the start of the season and seldom, if ever, modified for changes in the target crop.
As the crop morphology changes due to the plant growth or simple variation within the field, the desired application rate and placement of the spray droplets may vary accordingly. In areas of the field where spray target volume, mass or area is sparse, excessive material may be released and correspondingly, in areas of dense target, poor spray deposition may result in reduced biological efficacy of applied spray materials.
The following patents illustrate representative conventional nozzle assemblies which require tools for nozzle adjustment: U.S. Pat. No. 4,527,745 to Butterfield et al., entitled "Quick Disconnect Fluid Transfer System"; U.S. Pat. No. 4,438,884 to O'Brien et al., entitled "Quick Disconnect Nozzle"; U.S. Pat. No. 4,185,781 to O'Brien, entitled "Quick Disconnect Nozzle Connection"; U.S. Pat. No. 3,799,453 to Hart, entitled "Quick Disconnect Nozzle"; and U.S. Pat. No. 2,618,511 to Wahlin described above, all of which are incorporated by reference.
The Butterfield patent describes a quick disconnect spray nozzle assembly supplied with liquid from a pipe. The nozzle assembly includes a main body member forming a nipple which extends into the pipe through a hole in the wall of the pipe. Pressurized liquid within the pipe enters the nipple and passes downwardly through a central fluid passageway in the body member for discharge through a spray tip.
In order to lock the cap and the spray tip on the lower end of the body member, a pair of lugs on the body member cooperate with a pair of positioning and locking slots in the cap. This positioning of the cap sets the rotational position of the spray tip and, therefore, the direction of the spray pattern. Thus, the nozzle tip is tightly secured to the cap, and the orientation of the tip requires a corresponding orientation of the cap, which would require significant effort, special tools and trained applicators. In order to uncouple the cap, a biasing force is applied to the cap.
The O'Brien Pat. No. 4,438,884 illustrates a quick disconnect nozzle including a nozzle body and a nozzle tip. The nozzle body may be connected to a pipe and the nozzle tip is separable from the nozzle body by a twist type action. The tip is locked in the body by an interlocking engagement between undercut shoulders on the nozzle body and a pair of rounded projections on the nozzle tip which are engaged under the opposing shoulder by a twisting action.
This interlocked relationship is maintained by a sealing member which seals the connection between the nozzle body and the tip and exerts pressure therebetween. As a result of this rigid interlocked relationship between the nozzle tip and body, the orientation of the tip cannot be readily accomplished without tools and trained applicators. Moreover, the spray tip and retaining ring cannot be used without the exact mating nozzle body usually produced by and available from only a single manufacturer.
U.S. Pat. No. 4,185,781 to O'Brien describes another quick disconnect nozzle connection for a spraying tip and a nozzle body. The spraying tip is defined by a cylindrical inlet stem at one end of the tip. An arcuate section extends radially outwardly from the cylindrical surface of the stem and includes a recess. Retention segments extend radially inwardly over a cylindrical chamber adapted to receive the arcuate section of the spraying tip.
Each retention segment is adapted to mate with a corresponding recess in the arcuate section, in order to lock the nozzle body. A spring disposed between the nozzle body and the spraying tip maintains the body and tip in a locked relationship. Consequently, the patented nozzle design lacks orientation flexibility for the spraying tip.
The Hart patent describes yet another quick disconnect nozzle that is primarily intended for irrigation sprinklers. The nozzle includes a threaded fitting for connection to a sprinkler outlet having diametrically disposed L-slots. Each slot has a yieldable member having a yieldable wall provided with a retainer projection, and a nozzle member having diametrical pins for mating with the L-slots and interlocking with the fitting.
In none of the above systems can the spray nozzle be positioned or adjusted without shut-off of the liquid flow and removal of the nozzles or manual adjustment of the nozzle body using tools.
Another common attempt to address the nozzle orientation concern is to use multiple nozzle assemblies, such as three or even more at the same location as in Spraying Systems Co. TeeJet Part No. 24216, with different nozzle orientations or spray tip sizes. A typical conventional agricultural spray boom includes between 50 to 100 nozzles, while a cooling system in industrial applications could include 500 or more nozzles per duct. Obviously, this duplication of elements contributes to a substantial increase in the cost of fluid transfer systems, and the expense of maintaining such systems. Moreover, the spray tip alignment or position within each separate nozzle assembly cannot be adjusted without shut-down of the liquid spray flow and removal of the spray tips.
Thus, the need has become apparent for a single nozzle assembly which, in addition to being readily connectable to, and disengageable from a fluid transfer system by hand, should allow for a quick and precise nozzle orientation, without using special tools, shut-down of the spray liquid flow or removal of the nozzles. Such nozzle assemblies would, for instance, increase the accuracy and efficiency of the spray application process in order to reduce potential environmental pollution and decrease the overall amount of chemical applied.
As further illustrated by the Butterfield and Wahlin patents, complementary spraying parts, such as a filter or strainer and a check valve are conventionally inserted within the nozzle body. However, when maintenance is being performed on the site, in the field, and the nozzle member or cap is removed, these parts are loosely detachable and tend to readily self-disassemble. If found and recovered, cleaning and reorientation are necessary before refitting in the nozzle body to insure proper nozzle functioning. Additionally, the parts may become lost as they fall in dirt, foliage or rugged surroundings.
As a result, the applicator will need to remove his or her protective gloves to recover and clean the stray parts, sometimes placing them in the mouth to blow off the collected debris. As the soil might have already been sprayed with pesticides or other chemicals, conventional maintenance procedure could expose the applicator to hazardous situations.
Additionally, even if precautional measures are taken and the soiled parts were replaced with new parts, there remains the possibility of selecting and using the wrong size strainer, tip or valve. This mismatch may cause eventual clogging due to collected contaminants along the fluid path or improper operation of the spray system due to use of an incorrect check valve.
The logistics of replacing the parts of the nozzle assemblies, present yet another challenge, namely the lack of a uniform standard among the manufacturers. The replacement parts in conventional nozzle assemblies especially, the nozzle retaining cap and the nozzle body, should be purchased from the same manufacturers as the original parts, thereby significantly limiting the user's selection.
Therefore, it would be desirable to have a new nozzle assembly and a method of connecting it to a fluid delivery system. The nozzle assembly should securely house the tip, strainer, check valve and similar other components. It should further minimize the applicator's exposure to hazardous chemicals, and the likelihood of parts mismatch and malfunction. Additionally, the nozzle assembly should have a relatively simple design which encourages the setting of a uniform standard among the various manufacturers.